import re

html = '''
    <div class="board-item-content">
              <div class="movie-item-info">
        <p class="name"><a href="/films/1200486" title="我不是药神" data-act="boarditem-click" data-val="{movieId:1200486}">我不是药神</a></p>
        <p class="star">
                主演：徐峥,王传君,周一围
        </p>
<p class="releasetime">上映时间：2018-07-05</p>    </div>
    <div class="movie-item-number score-num">
<p class="score"><i class="integer">9.</i><i class="fraction">6</i></p>        
    </div>

      </div>
'''


# 2. 正则表达式
regex = '<div class="board-item-content">.*?<p class="star">(.*?)</p>'
pattern = re.compile(regex,re.S)

r_list = pattern.findall(html)
print(r_list)
# for item in r_list:
#     print(item.strip())


'''
 
 <div class="board-item-content">.*?<p class="star">主演：徐峥,王传君,周一围</p>
 
 
 <div class="board-item-content">.*?<p class="star">(.*?)</p>
'''